This is a very interesting topic to me as I believe that trends are a kind of limited time period conditioning. Saying that from now on something will be considered relevant good design is also a way of commercialising and ensuring the continuous need for new products. Is it a kind of manipulation? Yes, a little bit. When you see people around you dressed in a certain way, creating a certain kind of work, living in a certain kind of home, it is natural to want to “get with the programme”. It is a form of indirect manipulation in a more passive manner but again through the power of repetition. So how does it cease its existence after a while? How are trends different from advertisements? I think it is safe to say that too much of something is never good, especially if it is badly designed. When the trendy design hits the mass market, it becomes accessible to the commoners but the bad use of it in massive cycles of repetition to push sales make people get sick of it and it eventually dies out. I believe this is the reason why brands keep re-branding themselves, UI keeps updating, new advertisements keep popping up, repetition in a certain metric has the capacity to manipulate but sooner than later, it has to go.